A/C Unit Drawing Too Many Amps

[dmorse68]

Hi guys,

Just noticed my Dometic Penguin 2 unit in the living/kitchen area (zone 1) is drawing too many amp when the compressor kicks on. The fan motor starts up first, and draws 1.5 - 2 amps, then the compressor kicks on. When the compressor starts up, it draws about 24 amps initially for a half a second to a second, then settles back down to 14 amps the rest of the time it runs. Thoughts? Things to check?

David

[porkchop]

Absolutely normal, maybe even to the low side. Normal start up can be up to 300% easily

Bill

[dmorse68]

Absolutely normal, maybe even to the low side. Normal start up can be up to 300% easily

Bill

Perfect. Thank you Bill. I can rest easier now. It's 110 F - 114 F here all summer long so, I NEED them!

Interestingly enough, my zone 2 unit doesn't do this. However, my zone 1 unit is the one with a heatpump. Maybe that has something to do with it?

Thanks again,
David

[Cummins12V98]

Those temps are why I chose three 15k Units. Alicia said "when do AC units go out". That made me go with three as I had a unit hard start go out in Palm springs, CA in 100+ weather.

In 113 weather I can stay as cool as my wallet allows!

[CaptainPalapa]

One of those Micro-Air, SoftStart or EasyStart devices might be good for you. They seem pretty easy to install.

Jared with All About RV's just posted this video about a week ago:
https://www.youtube.com/watch?v=G-8o_E2bDYM

If you're not familiar with these devices, definitely check them out. Especially if you have more than one A/C unit and often end up on 30 amp. The 30 amp can RUN them, but not really START them as well, due to that load. These devices ramp up the compressor load to avoid throwing breakers.

[dmorse68]

Those temps are why I chose three 15k Units. Alicia said "when do AC units go out". That made me go with three as I had a unit hard start go out in Palm springs, CA in 100+ weather.

In 113 weather I can stay as cool as my wallet allows!
Yeah i am definitely lowering the life expectancies on my units here. When it’s 114F out, my two units are keeping my rig at 74F and using 60 kWh per day.

David

[Cummins12V98]

Yeah i am definitely lowering the life expectancies on my units here. When it’s 114F out, my two units are keeping my rig at 74F and using 60 kWh per day.

David


Actually that is good! 74 by your "T" stat of 74 by a real thermometer?

[Cummins12V98]

Actually that is good! 74 by your "T" stat of 74 by a real thermometer?

What model RV is yours? Fill in your public sig, it will help for future questions.

[CaptainPalapa]

When it’s 114F out, my two units are keeping my rig at 74F


I'm JEALOUS. I have a nice, shiny 44' Grand Design rig (2018). I have 3 A/C's. I'm on 50amp. I run all of them. It was 90 yesterday, and I can't keep the main room below 80 on some days. I know it's nonsense, it's not right. I should be FREEZING, but I'm not. It's even got this whole interconnected raceway so all three contribute to the entire house. Bedroom at night is fine. Garage / Office (toy hauler) is fine during the day, mostly. But that main room...oof.

At some point, I'm going to have to ask someone for help. I'm beyond my ken. Cold air does blow out of it, but .... there's something else going on that I don't understand.

[Cummins12V98]

I'm JEALOUS. I have a nice, shiny 44' Grand Design rig (2018). I have 3 A/C's. I'm on 50amp. I run all of them. It was 90 yesterday, and I can't keep the main room below 80 on some days. I know it's nonsense, it's not right. I should be FREEZING, but I'm not. It's even got this whole interconnected raceway so all three contribute to the entire house. Bedroom at night is fine. Garage / Office (toy hauler) is fine during the day, mostly. But that main room...oof.

At some point, I'm going to have to ask someone for help. I'm beyond my ken. Cold air does blow out of it, but .... there's something else going on that I don't understand.


Welcome aboard!

Fill in sig.

Sounds like one of your AC's is not preforming. ORRRRRR you have obstructions.

Remove all your returns and supplies. Have a roll of silver aluminum tape ready, you will need it to tape up the mess you will find. Keep your return air vents clean!

[CaptainPalapa]

Sounds like one of your AC's is not preforming. ORRRRRR you have obstructions.

Remove all your returns and supplies. Have a roll of silver aluminum tape ready, you will need it to tape up the mess you will find. Keep your return air vents clean!

Sig updated.

As far as I know, the only "returns" in these things are the vents themselves. In on one side, out on the other. With the crazy dump sliders. (Which I keep closed to force circulation to the main vents.) I've cleaned the filter screens.

I haven't looked at it with an eye towards adding any tape. (I need to pick some up, or toss in my next Amazon order, travel day is this Saturday after three weeks.) Like I said, the air that's coming out *IS* cold. But obviously the main room is the biggest, of course, and the tallest (which you'd think would help). And it's not like the A/C is shutting off either. It's running...kinda constantly. Even with our solar setup (very nice), I'm concerned about boondocking anywhere it might be warm. Heh. Seller (we've had it... three months?) did all the solar install (190w x 4, Viktron, BattleBorn, the works) and it's a good setup. (Used twice.)

Dunno, I'm babbling now.

[dmorse68]

Actually that is good! 74 by your "T" stat of 74 by a real thermometer?

By the T-stat

[dmorse68]

What model RV is yours? Fill in your public sig, it will help for future questions.
I’ve been looking for that public signature thing. Where’s it located so I can fill it out.

I have a 2018 DRV MS 36RSSB3

[Cummins12V98]

Click your name at top right then click about me.

[OneReallyOldGuy]

Ok guys, since we’re on the subject I have a problem with one of my units. It’s complicated so pour another cup and bear with me while I lay it out. My 2019 39DBRS3 has two dometic A/C’s. (No heat pumps). Wish I had gotten three but that’s another story.
Unit #1 works correctly all the time. Unit #2, the forward A/C works correctly most of the time. However it presents the following randomly. The unit starts and the little hour glass pops up on the control panel as usual. A few seconds later the compressor kicks in and the hour glass goes away. Between one and two minutes later the fan kicks up to high then about 30 seconds later the unit shuts down completely and the hour glass pops up again. The process repeats itself about two minutes later. The A/C blows cold air on each cycle but it doesn’t run long enough to cool the bedroom. I have the fan set on auto.
After anywhere from 10 minutes to a few hours of this cycling, the unit comes on and stays on until the normal cycle is complete and the set temperature is reached. It then operates normally for anywhere from a couple of hours to a couple of days.
A few more details:
Sometimes, randomly, when it’s operating “normally,” about 10 seconds after a cycle the fan kicks on for 5 seconds then turns off.
Sometimes I set the fan to medium and let it run because I get tired of listening to it cycle and if I watch the control panel the hour glass pops up for a couple minutes and goes off for a couple minutes so I assume the compressor is still fast cycling.
The problem is totally random and I don’t think it’s freezing up because upon starting the system after a five hour move in 90° weather it immediately began its cycling thing. It took forever to cool the coach that afternoon.
Outside temperature, humidity level, rain, shine, day, night have no bearing on it.
Thermostat setting has no bearing on it either. It doesn’t matter if it’s set to 72° or 68° or anywhere in between.
Of course every time the repair guy is on site at the RV Park we stay at the most it behaves normally. He says he can’t trouble shoot it if it’s working correctly.
Thanks for reading this, any thoughts or suggestions?
Phil

[Roam America]

I’m no HVAC guy by any stretch of the imagination. From what I’ve read and heard when the ac is short cycling it is due to low coolant. As the zone you refer to eventually gets to temperature it will be easier to maintain that temp than it was to get it there. If the fan is cycling on again later in the cycle, it may be starting to ice up.
Just a thaught.

[Cummins12V98]

Won't help your issue but I leave my fan in the ON position and gives more uniform cooling.

[OneReallyOldGuy]

I don’t think it’s freezing up because it’s so random and it resolves itself without turning off the unit to let it thaw. It was cycling when I woke up this morning but ran a full cycle by the time I got the coffee on. When I was composing my post it started its cycling thing again. Now it’s back to normal.
I’m thinking the condenser fan isn’t running sometimes causing a quick pressure build up which kicks the unit off. However I’ve never heard of a condenser fan not working intermittently. When they fail that’s it, they’re done.
Oh, and I have never, nor will I ever climb my old fat a** up on my roof so visually checking it is out of the question.

[OneReallyOldGuy]

Won't help your issue but I leave my fan in the ON position and gives more uniform cooling.

What setting do you leave it on? High, medium or low? I’ll put the bedroom unit on medium some nights just to drown out noisy neighbors or if it’s doing it’s cycling routine and I don’t want to hear it.

[Cummins12V98]

We always use the "ROOF FAN" in the bedroom for white noise.

When using the AC we either use Med or High in bedroom. Living area we run full ON all the time.

[ElectricBill66]

Hi guys,

Just noticed my Dometic Penguin 2 unit in the living/kitchen area (zone 1) is drawing too many amp when the compressor kicks on. The fan motor starts up first, and draws 1.5 - 2 amps, then the compressor kicks on. When the compressor starts up, it draws about 24 amps initially for a half a second to a second, then settles back down to 14 amps the rest of the time it runs. Thoughts? Things to check?

David The amperage that you have measured appears to be normal. The initial start-up current is normal. The amperage for a 13,000 or a 15,000 BTU air conditioner on max cool is normally 16.1 amps. Slightly less on low cool but not by very much since all that is happening is the blower fan is at a reduced speed. Compressor still pulls same amount of current wether its on hi or low cool. If anything, your A/C is pulling less amperage. I don't know the specifics about your model but a low freon charge could cause a lower than normal current situation.
If its cooling fine, I'd say theres no problem with it. The air conditioner is on a dedicated 20 amp breaker for the reason it can draw up to 16.1 amps.
Hope this helps.

[porthole]

Hi guys,

Just noticed my Dometic Penguin 2 unit in the living/kitchen area (zone 1) is drawing too many amp when the compressor kicks on. The fan motor starts up first, and draws 1.5 - 2 amps, then the compressor kicks on. When the compressor starts up, it draws about 24 amps initially for a half a second to a second, then settles back down to 14 amps the rest of the time it runs. Thoughts? Things to check?

David

Google "locked-rotor amperage"

[porthole]

Ok guys, since we’re on the subject I have a problem with one of my units. It’s complicated so pour another cup and bear with me while I lay it out. My 2019 39DBRS3 has two dometic A/C’s. (No heat pumps). Wish I had gotten three but that’s another story.


Oh, and I have never, nor will I ever climb my old fat a** up on my roof so visually checking it is out of the question.



I didn't see if you mentioned whether this problem is on 50 or 30 amp service.

Have you been in any areas where the debris from trees will clog a coil?
I've never been, so don't know what trees they are, but I've seen pictures of AC coils that look like they are covered in raw cotton.

We also have a 2019 39DBRS3, with the 3 AC's, and I'm glad we do.

If we are on 30 amp the load management system will dump the 2nd AC compressor if anything comes on while running. If the extra load ends soon enough the compressor delay (2.5 minutes I think) will bring up the hour glass symbol.
This is with 2 AC's running. If I try and run 3 the load management will dump the first 2 anyway.

If you can do the add on, the third AC is a real benefit in the heat.

On 'good' 50 amp service in 95+ temps we can keep the inside around 72.
On 30 amp though we are lucky to keep it around 80 with only 2 AC's and one kicking out as loads vary.

[OneReallyOldGuy]

Hey Duane, I’m on 50 amp with 125v on both legs, no faults. Hope I can find someone who really knows their stuff. Is it the A/C which blows cold when it runs, or the thermostat, or the load management system?
The electrical system on this thing is going whaco. Along with the A/C problem the LED lights are failing left and right, the sea level gauges on the black and gray tanks work sometimes and sometimes they show “OPN” (open circuit), and this morning the microwave quit. Display turned off and it’s dead. Got power to the plug.
I’m pretty sure this coach was wired starting on a Friday and finished on a Monday.
Ok, rant over.
Thanks,
Phil